How to get lamp object?
Blender object basics.

The lamp objects in bpy.data.lamps is the data part of a lamp object o. A lamp object has o.type == "LAMP" and o.data is a lamp object from bpy.data.lamps.

To get all lamp objects in file

lamp_objects = [o for o in bpy.data.objects
                if o.type == 'LAMP']


all in file that use a lamp named "Lamp"

lamp = bpy.data.lamps.get("Lamp")
lamp_objects = [o for o in bpy.data.objects
                if o.type == 'LAMP' # need this since
                and o.data is lamp] # o.data is None for empties


for all in context scene

scene = bpy.context.scene
lamp_objects = [o for o in scene.objects
                if o.type == 'LAMP']


for all in context selected objects

lamp_objects = [o for o in bpy.context.selected_objects
                if o.type == 'LAMP']


To move all lamps to local position (0, 0, 0)

for o in lamp_objects:
    o.location = (0, 0, 0)


To move all lamps to global origin

for o in lamp_objects:
    o.matrix_world.translation = (0, 0, 0)